The price of the cryptocurrency in the Southern African nation jumped as high as $13 499, almost double the rate at which it trades in international markets, according to prices cited on Golix’s website.

Golix, an unregulated platform that also trades other cryptocurrencies, has been in operation since 2014. Prices for Bitcoin are set by supply and demand, according to Taurai Chinyamakobvu, co-owner of the exchange. Sellers are paid in U.S. dollars deposited electronically, which can only be converted at a steep discount on the black market.